A poll by Portugal’s Catholic University for public broadcaster RTP estimated that the Socialists collected between 37%-42% of the vote on Sunday, with their main rival, the centre-right Social Democrats taking 30%-35%.
The centre-left Socialist Party won the most votes in Sunday's legislative election in Portugal and is close to securing an absolute majority.
With more than 98% of the votes counted, the Socialists (PS) secured nearly 41.65% of the vote while their centre-right rivals, the Social Democrats (PSD), had managed to get 27.94%.
The far-right Chega (Enough) party made significant gains and was third with 7.15% of the vote.
The snap election was triggered two months ago when lawmakers rejected the minority Socialist government’s spending bill and the country’s president dissolved parliament.
Opinion polls had suggested that the Socialists and Social Democrats were in a tight race.